There are times during a battery's life when it would be desirable to control its internal temperature. For example, it would be desirable during initial formation of a Pb-acid battery to remove the heat generated therein during the formation process and thereby accelerate the formation process without damaging the battery. Moreover, in the case of traction batteries for electric vehicles, it would be desirable to remove heat from the battery pack (i.e., a plurality of multicell, monobloc batteries electrically coupled together) during periods of high rate charge or discharge and thereby prevent damage to the battery pack. Still further, during the charging of such electric vehicle battery packs it would be desirable to insure that all the individual batteries, and indeed all the individual cells are at about the same temperature so as to insure proper charge balance from one cell to the next within the pack. Finally, in cold climates it would be desirable to preheat the battery before usage and/or to heat the battery while in use to achieve optimal output therefrom.
Techniques used heretofore for heating/cooling batteries have not been particularly effective to evenly rapidly add/remove large amounts of heat from a battery. This is particularly true for gas recombinant batteries which utilize electrolyte-immobilizing, interplate separators and thereby prevent convection cooling of the battery incident to the circulation of electrolyte in each cell. It is particularly difficult to heat/cool monobloc batteries wherein a plurality of cells are housed contiguously side-by-side each other within a single container, which makes it impossible to circulate coolant (e.g., air) around the outside of each cell.
It is an object of the present invention to provide a unique monobloc, multicell electric storage battery having a substantially planar, liquid-heated/cooled heat exchanger in each cell of the battery which heat exchanger has a high heat exchange surface area confronting a substantial area of at least one plate of each cell element in the battery so as to add and/or extract heat from such element under extreme operating temperature conditions. It is another object of the present invention to incorporate such a heat exchanger into the intercell partition of a monobloc battery container. It is still another object of the present invention to locate such heat exchanger within a cell element itself. These and other objects and advantages of the present invention will become more readily apparent from the detailed description thereof which follows.